Description

Oneotoceras percurvatum
Nautiloid
Lower Ordovician
Gasconade Dolomite
Ozarks, Sullivan, Missouri, USA

48mm nautiloid.

Oneotoceras is an extinct genus of nautiloid from the Ordovician of North America (sites in the U.S.A.).  It lived at a time when nautiloids were becoming the apex predators of the seas.  These animals later declined in diversity during the Devonian but continued to be significant elements of marine faunas over the rest of the Paleozoic Era.

Today, only a few species survive in areas of the Indo-Pacific.